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Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
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Albuquerque, NM|The University of New Mexico
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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Guangliang Chen, Zhijian Zhang, Zhaofei Tian, Thompson Appah, Lei Li, Xiaomeng Dong, Peizheng Hu
Nuclear Science and Engineering | Volume 188 | Number 3 | December 2017 | Pages 270-281
Technical Paper | doi.org/10.1080/00295639.2017.1367568
Articles are hosted by Taylor and Francis Online.
In a subchannel analysis, the assumptions of the physical models may be invalid when three-dimensional (3-D) effects play an important role because a large-scale model cannot consider a small-scale physical process. However, in a pressurized water reactor (PWR), the flow process has a high 3-D effect due to the effect of complex structures, such as dimple, spring, and mixing vane. A computational fluid dynamics (CFD) analysis can give more detailed physical information. So, the modeling assumptions of the subchannel analysis codes were analyzed using data from CFD analysis, and some issues were found: The spatial acceleration of the cross-flow rate and the viscous force from fluid to fluid should not be neglected; the lateral pressure gradient not only is a driving force but also can be a resistance at some vertical range; the traditional “resistant force term” has the same direction with the cross flow at some vertical ranges. To improve the subchannel code, one physical term considering both the driving and the resistance effect is suggested to be added in the traditional transverse momentum equation. The solution for this new term and the method using spatial acceleration of the cross flow were also provided.